How to automatically know which Facebook friends are using the publisher’s messenger? Is there a section in Facebook to know which contacts are using the publisher’s messenger app on their mobiles, instead of directly asking the contacts?
When you log on to facebook from your desktop and turn on your chat, you can see small mobile symbols next to the names that use facebook messenger from their mobile. The people who are online from their desktops are shown by a small green dot if they are online. I hope this answers your question?!
But can the mobile symbol also indicate 'facebook sms activated'? even though messenger would not be installed
No, I don't think so.
Please tell conversely , how to know that facebook sms is activated even if messenger would not be installed